1 Department of Gastroenterology, University Hospital of Ioannina, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece (Dimitrios S. Politis, Konstantinos H. Katsanos, Dimitrios K. Christodoulou).
2 Department of Pathology, University Hospital of Ioannina, Ioannina, Greece (Eleni Triantafyllidi).